When comparing Bugsnag vs Kwok Information Server, the Slant community recommends Kwok Information Server for most people. In the question“What are the best free bug-tracking tools for programming? ” Kwok Information Server is ranked 11th while Bugsnag is ranked 12th. The most important reason people chose Kwok Information Server is:
No client software needed.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Great documentation
Clear, concise documentation. Plus docs on cross-domain script errors and enabling CORS.
Pro Email, chat, sms notifications
Bugsnag can be set up to send email notifications as soon as exceptions occur. It can also integrate with a number of third-party services that can be used for notifications including Campfire, HipChat, Twilio SMS and custom solutions via Webhook.
Pro Automatic issues/ticket creation
Bugsnag integrates with a wide variety of 3rd party tools to automatically create issues or tickets. Integrations include GitHub, BitBucket, UserVoice, Trello and many, many others.

Pro Has a free plan
After a two-week full-featured free trial period the user is limited to 2,000 errors/month, 1 user and 1 project.
Pro Exceptions are grouped
Bugsnag groups similar exceptions together displaying the number of occurences so that there's no need to deal with each instance of the error separately.
Pro Exceptional documentation organization
Their documentation was well organized, easy to search through for the platform of choice and quick work of full product integration.
Pro Supports Unity 3D
Drop in place integration with Unity 3D, only a simple API Token configuration on game object and everything was up & running with almost zero code written.
Pro Supports phabricator integrations
Not many products have decided to finally start doing this, phabricator now has a champion.

Pro Source map support

Pro Stack traces
Pro Client libraries are open source

Pro Report uncaught errors
Pro Good web UI
Pro Web based
No client software needed.
Pro Positive reviews
Positive reviews on SourceForge.
Pro Win, Mac, Linux
Multi platform.
Cons
Con The tool seems flaky
De-obfuscation doesn't always work on react-native projects.

Con Blocked by ad blockers by default
Bugsnag is blocked by the AdBlock EasyPrivacy filter.
Con Limited
Might be too limited for advanced users, there seems to be no integration with version control systems like GIT or SVN.
